1. Field of the Invention
Embodiments of the invention relate to a semiconductor device, a metal electrode member, and a method of manufacturing a semiconductor device.
2. Description of the Related Art
Conventionally, for example, a semiconductor device, such as a semiconductor module, has a configuration in which a semiconductor chip and other component members are soldered to a conductive plate on a surface of an insulated circuit board. The conductive plate and an external electrode terminal are electrically connected by fitting the external electrode terminal into a metal member having a hollow cylindrical shape (hereinafter, cylindrical contact member) soldered to the conductive plate on a surface of the insulated circuit board (for example, refer to Japanese Laid-Open Patent Publication No. 2011-150833 and Japanese Laid-Open Patent Publication No. 2012-231042).
When the semiconductor chip on the insulated circuit board and the external electrode terminal are connected, after the cylindrical contact member is mounted on the conductive plate of the insulated circuit board by soldering, a pin-shaped external electrode terminal is press-fitted in to a main body part of the cylindrical contact member, the main body part having a hollow cylindrical shape. An inner diameter (diameter) of the main body part of the cylindrical contact member is slightly smaller than an outer diameter of the external electrode terminal to suit fitting dimensions for fitting with the external electrode terminal.
A configuration of components of a conventional semiconductor module will be described. FIG. 9 is a cross-sectional view of a configuration of components of a conventional semiconductor module. FIG. 10 is a plan view of a planar shape of another end of an external electrode terminal at cutting plane A in FIG. 9. As depicted in FIG. 9, a cylindrical contact member 110 of the conventional semiconductor module has a main body part 101 having a hollow cylindrical shape, and flanges 102, 103 provided at both open ends 101a, 101b of the main body part 101, respectively.
The flange 102 of one open end 101a of the main body part 101 of the cylindrical contact member 110 is bonded by soldering 125 to a conductive plate 122 of a front surface of a layered substrate 120. The layered substrate 120 is constituted by the conductive plate 122 formed on a front surface of a ceramic substrate 121 by a copper (Cu) foil; the layered substrate 120 is further constituted by a copper foil 123 formed on a rear surface of the ceramic substrate 121. The cylindrical contact member 110 is electrically connected to a semiconductor chip (not depicted), via the conductive plate 122 and a non-depicted wire.
One end 111a of an external electrode terminal 111 is press-fit into the main body part 101 (a hollow part 104) of the cylindrical contact member 110 to be fitted to the cylindrical contact member 110 and is thereby fixed. The external electrode terminal 111 is electrically connected to a semiconductor chip 124, via the cylindrical contact member 110. Another end 111b of the external electrode terminal 111 protrudes outside a resin case 126 from a thru-hole 127 of the resin case 126.
Further, the other end 111b of the external electrode terminal 111, at the part protruding outside the resin case 126, is connected to a printed circuit board (PCB) 131 by solder (not depicted). Alternatively, the other end 111b of the external electrode terminal 111, at the part protruding outside the resin case 126, is press-fit into a through-hole 132 of the printed circuit board 131 to be in contact with an electrode (hereinafter, through-hole electrode) 133 provided along an inner wall of the through-hole 132 and is electrically conducted with a circuit part on the printed circuit board 131.
When the external electrode terminal 111 is press-fit into the through-hole 132 of the printed circuit board 131, an outer diameter of the other end 111b of the external electrode terminal 111 is slightly larger than an inner diameter the through-hole electrode 133 provided along an inner wall of the through-hole 132 to suit fitting dimensions for fitting with the through-hole 132. By setting the fitting dimensions in this manner, the external electrode terminal 111 and the through-hole electrode 133 are caused to contact each other due to elastic forces of the external electrode terminal 111 and the through-hole electrode 133.
The external electrode terminal 111, for example, has an edge shape bent at a predetermined angle so as to have line symmetry with respect to a central axis z of the external electrode terminal 111 (for example, a substantially V shape) (FIG. 10), or an edge shape branched plural times with each branch partially jutting out in a protruding shape in a direction x (or direction y, or both directions x, y) orthogonal to the central axis z of the external electrode terminal 111 (for example, refer to Japanese Laid-Open Patent Publication No. 2016-012604). By processing the external electrode terminal 111 to have such an edge shape, the outer diameter of the other end 111b of the external electrode terminal 111 becomes slightly larger than the inner diameter of the through-hole electrode 133 provided on the inner wall of the through-hole 132.